andthatcitiesarekey to theeconomy.largecitiesproduce83% of economic output in the united states. the 30 largest cities in the u.s. account for half of all gdp. we're all in favor of good infrastructure until it comes time to pay for it. you say that some money can come from the private sector, we've had high-profile examples of public-private partnerships that have gone wrong. how do city governments make sure that city residents get what they pay for? >> i don't think there's any simple answer to this. one reason we might want a national infrastructure bank is not for the money, but to provide oversight, you have somebody to go to when you have a project, a regulator. an interlocutor. we should alloy private money. there's an additional problem. about so-called eminent domain. you can't just clear things out in china they used to at least just knock on your door and say you're moving. we're building a road here. you got to move out of your apartment tomorrow. we can't do that. it makes it trickier in our older cities to rebuild in the way they did in china. >> it's an interesting analo

you some of thefigures.largecitiesproduce83% of economic output in the united states. the 30 largest cities in the u.s. account for half of all gdp. now, we're all in favor of good infrastructure until it comes time to pay for it. you say that some money can come from the private sector, but we've had some high-profile examples of public/private partnerships that have gone wrong. how do city governments make sure that city residents get what they pay for? >> i don't think there's any simple answer to this. and by the way, one reason when he we might want a national infrastructure bank is not for the money but just to provide oversight and ombudsman so that you have somebody to go to when off project or regulator, an interlocutor perhaps. we should definitely allow private money. there is an additional problem, and richard probably knows more about this, about so-called eminent domain, where you can't just clear things out. in china, they used to at least just knock on your door and say you're moving, we're building here a road here. you have to move out of your parm tomorrow.